题干

如图是细胞核的结构模式图,下列关于各结构及功能的叙述正确的是(  )

A:①是所有生物遗传物质的主要载体

B:所有细胞中核糖体的形成都与②有关

C:③属于生物膜系统,把核内物质与细胞质分开

D:④是大分子物质(如DNA)出入细胞核的通道

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答案(点此获取答案解析)

C

同类题2

任务型阅读

The Science of Risk-Seeking

    Sometimes we decide that a little unnecessary danger is worth it because when we weigh the risk and the reward, the risk seems worth taking. ____ Some of us enjoy activities that would surprise and scare the rest of us. Why? Experts say it may have to do with how our brains work?

    The reason why any of us take any risks al all might have to do with early humans. Risk-takers were better at hunting, fighting, or exploring. ____ As the quality of risk-taking was passed from one generation to the next, humans ended up with a sense of adventure and a tolerance for risk.

    So why aren't we all jumping out of airplanes then? Well, even 200,000 years ago, too much risk-taking could get one killed. A few daring survived, though, along with a few stay-in-the-cave types. As a result, humans developed a range of character types that still exists today. So maybe you love car racing, or maybe you hate it. ____

    No matter where you are on the risk-seeking range, scientists say that your willingness to take risks increases during your teenage years. ____ To help you do that, your brain increases your hunger for new experiences. New experiences often mean taking some risks, so your brain raises your tolerance for risk as well.

    ____ For the risk-seekers a part of the brain related to pleasure becomes active, while for the rest of us, a part of the brain related to fear becomes active.

    As experts continue to study the science of risk-seeking, we'll continue to hit the mountains, the waves or the shallow end of the pool.

A. It all depends on your character.

B. Those are the risks you should jump to take.

C. Being better at those things meant a greater chance of survival.

D. Thus, these well-equipped people survived because they were the fittest.

E. This is when you start to move away from your family and into the bigger world.

F. However, we are not all using the same reference standard to weigh risks and rewards.

G. New brain research suggests our brains work differently when we face a nervous situation.

同类题4

任务型阅读

    Do you like reading? How often do you go to a bookshop? To compete with online sellers, traditional bookshops have tried everything to win customers. And it is true that a great bookstore can encourage people to read in many ways. Here are some good shops in China and other countries that are worth a visit.

Eslite Bookstore, Suzhou

    The Eslite Bookstore is very popular among young people in Suzhou. It has fashion shops, cafes and other places. It also holds many reading-relative activities including discussions and talks with famous writers.

Sanlian Taofen Bookstore, Beijing

    It is 11:30 pm. But the Sanlian Taofen Bookstore is shining brightly. Many people are staying inside for one thing: to read. The bookstore is open 24 hours a day. It's the first bookstore of its kind in Beijing.

Shakespeare & Company, France

    France doesn't have Shakespeare but it has Shakespeare & Company. Many great writers used to meet here including Ernest Hemingway. Today, it helps young writers by allowing them to live and work here.

Strand Bookstore, US

    Strand Bookstore is a second-hand bookstore. It sells books for $2-3 each, much cheaper than they used to be. Sometimes you can even find very old and rare books here. For example, a Shakespeare book that was published in 1632 is worth $125,000!

阅读以上信息,用恰当的词完成下面的表格,每空一词。

Good bookstores that are worth ____

Eslite Bookstore, Suzhou

·Many young people like it because it is fashionable.

·Readers can also ____ the books here and have talks with famous writers.

Sanlian Taofen Bookstore, Beijing

·People can read here as ____ as they want because it is never closed.

Shakespeare Company, France

·Many great writers used to meet here.

·Young writers are ____ to live and work here.

Shakespeare & Company, France

·You can buy books at a ____ price because they are used.

·You can even find old and rare books which are very valuable.